JPS6041974Y2 - Microwave sterilizer - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for heating and sterilizing a liquid using microwaves.

Conventionally, a method using steam has been used as a means for continuously heating and sterilizing liquids.

This method can be roughly divided into (1) direct heating method and (2) indirect heating method.

The direct heating method is a method in which steam is injected directly into the product, making it possible to sterilize the product in a relatively short period of time.It has the advantage of being less prone to scale deposition, but has the disadvantage that the steam comes into direct contact with the product. This means that the steam needs to be pure.

This is not easy to do, and the equipment and operating costs are high.

Next is the indirect heating method, which has the advantage that there is no risk of contamination of foreign matter from the steam and lower equipment costs compared to the direct heating method, but the heat from the steam is transferred to the product through heat transfer walls such as stainless steel. Because of the so-called external heating method, it takes time to heat and has the drawback of easily causing deterioration of flavor and nutritional value.

In addition, scale deposits tend to occur on the heat transfer surface, which poses maintenance problems.

This invention was made to improve these shortcomings.
Here, we provide a sterilization device that can perform sterilization treatment in a short time and produce high-quality products.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a flowchart of the microwave sterilizer, and FIG. 2 is a sectional view of the microwave heating section.

In FIG. 1, 10 is a raw material tank, 12 is a pump installed in a pipe line 14, 16 is a microwave heating section, and 18 is a cooling section. Liquid raw materials to be sterilized, such as foods, are stored in the tank 10. The heating section 16 is heated by the pump 12 from
After being sterilized by microwave irradiation, it passes through the pipe 20 to the cooling section 18, where it is cooled and then discharged.

Here, the heating section 16 has a structure as shown in FIG.

In the figure, 22 is a cylindrical shell, into which cylinders 24 and 26 are inserted and fixed.

The inner cylinder 24 is fixed at both ends to the end plate 28 of the shell, and the outer cylinder 26 has its upper end fixed to the cylinder and is closed, but its lower end is open.

The inside of the inner cylinder 24 is a sealed chamber in which the microwave irradiator 30 is housed.
4 and 26 is a relatively narrow passage 32 for the raw material, and the pipe line 14 is connected to the outer cylinder 26 and the shell 2.
2 is a relatively large passage 3 for the passage of the raw material.
4, and the above-mentioned discharge pipe 20 is connected.

Next, a sterilization operation using the sterilizer having the above configuration will be described.

The raw material is pumped from the raw material tank 10 to the microwave heating section 16 by the pump 12 .

The raw material first enters the first passage 32 and falls freely in a ring shape along the walls of both the inner and outer cylinders 24, 26.

While the raw material is falling freely, it is rapidly heated by the microwave irradiator 30 attached to the center of the apparatus, and as a result, the raw material rises to the sterilization temperature.

The raw material heated to the sterilization temperature is led to the second passage 34, where it is heated again by the microwave irradiator 30.

For this reason, it is desirable that the walls of the inner and outer cylinders 24 and 26 be made of Teflon or the like, which has excellent microwave permeability.

The second passage 34 is wider and has a larger heat capacity than the first passage 32, and most of the microwaves are absorbed in the first passage, and the remaining microwaves reach the second passage. becomes a so-called heat retention state.

As a result, the temperature of the product is maintained until it reaches the inlet of the pipe line 20, and the temperature is maintained at a predetermined F.

You can get the value.

Further, since the raw material in the second passage 34 also preheats the raw material in the first passage 32, the rapid sterilization properties of the microwave can be promoted.

The product heat-sterilized in this way is passed from the pipe line 20 to the cooling section 1.
8, cooled by conventional methods, and transferred to an aseptic filling machine (not shown).

As described above, the present invention surrounds the microwave irradiator 30 with the cylindrical body 24, surrounds the outside with another cylindrical body 26, further surrounds the outside with the shell 22, and allows fluid to flow between the inner and outer cylindrical bodies. forming a first passage, and forming a second passage continuous with the first passage between the outer cylinder 26 and the shell 22;
The microwave sterilizer is characterized in that the fluid is sterilized by being irradiated with microwaves from the irradiator while the fluid is being pumped from the first passage to the second passage. This microwave irradiation device can perform heating for sterilization and heating for heat retention.

Therefore, the predetermined F can be efficiently achieved.

You can get the value.

Next, examples will be shown.

Example When orange juice was sterilized using an irradiator with a microwave frequency of 2450 MHz and an output of 5 KW, the product temperature rose to 100°C in the W sand diameter as shown in Figure 3, and was held at 100°C for 25 seconds. It was then cooled to 85°C and filled with aseptic filling material.

The obtained product had a better flavor than one sterilized using a conventional method, and was of very high quality with no browning.

[Brief explanation of drawings]

FIG. 1 is a flowchart of the microwave sterilization system. FIG. 2 is a vertical sectional view of the microwave irradiation device according to the present invention. FIG. 3 is a heating temperature/hour relationship graph showing an example of sterilization treatment using the above-mentioned irradiation device. 30...Microwave irradiator, 24. 2
6... cylinder body, 22... shell body.

Claims (1)

[Scope of utility model registration request] The microwave irradiator 30 is surrounded by a cylindrical body 24, the outside of which is surrounded by another cylindrical body 26, and the outside of that is further surrounded by a shell 22, forming a first passage for fluid between the inner and outer cylindrical bodies. A second passageway is formed between the outer cylindrical body 26 and the shell body 22, which is continuous with the first passageway, and the fluid is pumped from the first passageway toward the second passageway. A microwave sterilizer characterized in that the fluid is sterilized by irradiating the fluid with microwaves from the irradiator.